Among the most commonly diagnosed neurodevelopmental disorders, Attention-Deficit/Hyperactivity Disorder features a pattern of inattention and/or hyperactivity that interferes with functioning or development. Typically identified in childhood, symptoms of ADHD need to be evident across multiple settings and caregivers in order for the diagnosis to be confirmed.1
While individuals with ADHD are often impacted throughout their lives, symptoms can be managed with behavior therapy and/or medication.
What Is ADHD?
More formally, Attention-Deficit/Hyperactivity Disorder requires the presence of symptoms related to inattention, hyperactivity/impulsivity, or both.2 It is important to note that, in isolation, any of the characteristics of the disorder can be observed throughout typical childhood development. In order to meet criteria for ADHD, symptoms must be present for at least 6 months1 and significantly impact academic, social, and adaptive abilities.
It should be strongly noted that individuals with ADHD are not all impacted in their ability to pay attention. More accurately, these individuals are attending to the wrong things in the environment. They can be experts in putting together puzzles, building Legos, and might play video games for hours. Their deficits often lie primarily in sustained focus in situations and events that do not pique their intrinsic interests or result in immediate rewards.
Symptoms of ADHD are first observed in childhood (i.e. before age 12). These children often display difficulties with persistence in the face of challenging tasks, excessive motor activity (hyperactivity), and in thinking through the consequences of their actions impulsivity).
With regard to impulsive behaviors, individuals with ADHD are best described as having “ready, fire, aim” behaviors; they often act without thinking about the impact of their behaviors, demonstrating poor foresight and planning. These behaviors may be the product of an underlying inability or intolerance to delay gratification.
Types of ADHD
Types of ADHD include ADHD with Predominantly Inattentive Presentation, ADHD with Predominantly Hyperactive/Impulsive Presentation, and ADHD with Combined Presentation.
ADHD with Predominantly Inattentive Presentation1
Individuals meeting diagnostic criteria for this subtype of ADHD present with fewer symptoms of hyperactivity.
Inattentive symptoms typically manifest in some or all of the following ways:
- Difficulty with close attention to detail across multiple contexts, resulting in frequent mistakes and creating a negative impact on work productivity (e.g., at school, work, or during non preferred leisure activities).
- Difficulty maintaining attention in non preferred tasks or activities. Examples include challenges remaining on-task during reading tasks or lengthy conversations.
- Demonstrates “wandering attention” even without the presence of clear distractions in the environment.
- Difficulty following through with tasks (preferred or nonpreferred). These individuals may often start projects with relative ease but fail to complete them.
- Challenges related to organization; including completing multiple-step actions, time management, and keeping things in order.
- Avoidance of tasks that require persistence of mental effort (e.g., completion of homework, lengthy forms, or monotonous review of information).
- Difficulty holding onto things necessary for task completion (e.g., eyeglasses, car keys, cellphone, wallet, etc.)
- Easily distracted by stimuli in the environment (includes fleeting, unrelated thoughts).
- Forgetful during activities of daily living (e.g., routine chores, errands, returning calls, keeping appointments).
ADHD with Predominantly Hyperactive/Impulsive Presentation1
Individuals meeting diagnostic criteria for this subtype of ADHD have significant difficulty with behavioral excess (i.e. behaviors that are more overt, and at times, socially stigmatizing).
Hyperactive and/or Impulsive symptoms typically manifest in some or all of the following ways:
- Frequent fidgeting or tapping with hands or feet; squirming in seat
- Inability to remain seated during times when doing so is expected (e.g., while working in a classroom or office)
- Excessive motor activity (e.g., running, climbing, restlessness) in situations where it may be inappropriate
- Difficulty engaging in quiet leisure activities (e.g. private reading in a library)
- Behavior characterized as being “driven by a motor” (e.g., unable to remain still for an extended period of time)
- Excessive talking
- Inability to inhibit one’s own communicative behavior (e.g., blurts out answers to questions, difficulty waiting for one’s turn in conversation)
- Interrupts or intrudes on others (e.g., takes over others’ activities, uses others’ things or invades others’ space without asking)
ADHD with Combined Presentation1
Individuals meeting diagnostic criteria for this subtype demonstrate significant symptoms in both Inattentive and Hyperactive/Impulsive categories.
Signs of ADHD
Although not specific to ADHD exclusively, children with ADHD can also present with mild delays in language, motor, or social development.1 Many parents first report excessive motor activity when their child is a toddler, but these symptoms can often be difficult to distinguish from typical development before age 4.
Most commonly, ADHD is diagnosed during elementary school years (ages 5-7) where symptoms of inattention become more impairing. Symptoms of impulsivity, excessive activity levels, and poor focus tend to be stable throughout early adolescence. For many individuals, hyperactive behaviors tend to lessen as they age and give way to fidgeting, impatience, and/or general restlessness.
Adolescents with ADHD tend to demonstrate more educational difficulties, including more failing grades and a higher chance of dropping out of school, than their neurotypical peers. They also have more difficulty in their relationships with peers, teachers, siblings, and parents.3
As adolescents develop into adulthood, research suggests a reduction in core symptoms of ADHD.4 In adults, qualities of poor planning and inattention tend to persist throughout their lifetime. Older individuals who continue to meet criteria for ADHD tend to have more problems with adjustment and poorer mental health than comparison groups. These adults also continue to have difficulty with impulsivity, which can lead to financial and/or legal problems (i.e. these individuals are more likely to switch jobs, get speeding tickets, and have driving accidents).
However, some research has demonstrated that adults who were hyperactive youngsters use their energy more adaptively; many may work multiple jobs, may choose jobs that are more active, and/or may work longer hours. In this way, the aimlessness of childhood restlessness has given way to more purposeful activity-seeking in adulthood.
As some adults who present to physicians and mental health professionals have not previously been diagnosed in childhood, additional criteria beyond medical history have been suggested. It should be noted that each criterion is only met if the behavior occurs more frequently and is more impairing than individuals with the same developmental age.
These criteria include:4
- Sense of underachievement/low self-esteem
- Difficulty getting organized
- Chronic procrastination
- Trouble with follow-through on tasks
- Tendency to speak one’s mind, with little insight into the timing or appropriateness of the remark
- Frequent search for high stimulation
- Intolerance for boredom
- High distractibility
- Often creative, intuitive, and highly intelligent
- Difficulty following “proper” procedure
- Low tolerance for frustration
- Impulsive
- Tendency to work endlessly
- Sense of insecurity or worry
- Mood swings
- Restlessness
- Tendency toward addictive behavior
Current research suggests that attention-deficit/hyperactivity disorders is a chronic condition, with approximately half of children continuing to exhibit symptoms and impairment into adulthood. ADHD is also associated with other types of psychiatric disorders, including oppositional defiant disorder (ODD), conduct disorder, mood and anxiety disorders, and substance use disorders.5
What Causes ADHD?
The causes of ADHD include brain structure, brain chemicals, genetics, and environment.
Structural Brain Causes6,7
ADHD has been noted to affect about 5% of children, with up to 65% having symptoms persist into adulthood. Use of anatomic studies (MRI/FMRI) suggest atypical brain structures among individuals with ADHD. Most notably, scans have shown overall decreases in brain volume, with particular affected areas including the prefrontal cortex, basal ganglia, cerebellum, and parieto-temporal regions.
In addition, longitudinal studies suggest that young children have delays in prefrontal cortical development. The impact of these affected areas in the brain is thought to manifest as delays in cognitive processing, including working memory, as well as motor and attention planning.
Chemical Brain Causes8
Additional research has implicated several biological bases for the symptoms of ADHD, including deficits in the reward/motivational centers of the brain also known as the dopamine pathway. Specifically, brain neuroimaging studies have demonstrated disruption in the dopamine pathway, which is hypothesized to be linked to core symptoms of attention and impulsivity.
Genetic Causes9
Previous familial research has established that childhood and adult ADHD is highly heritable, with estimates around 40% heritability. Family studies suggest that there is a high risk for ADHD among first-degree relatives, particularly those for whom symptoms persist into adulthood.
However, genetic research has been unable to identify specific genes that are responsible for conferring heritability in families. ADHD is not associated with specific physical features, though subtle motor delays and neurological signs may occur.
Environmental Causes9
There have been some environmental factors linked to increased likelihood for diagnosis of ADHD. Specifically, very low birthweight (less than 3 pounds) increases the risk for ADHD by 2-3 times. It should be noted that most children with below-average birth weight do not go on to develop ADHD. There have been some connections between environmental toxins and a later ADHD diagnosis, including lead exposure, alcohol exposure, and smoking during pregnancy.
What Does NOT Cause ADHD
Despite some assertions by past research and non-experts, ADHD is not caused by poor parenting, refined sugar, food additives/allergies, video games, or technology.
How Is ADHD Diagnosed?
Attention-deficit/hyperactivity disorder can be reliably diagnosed in children, adolescents, and adults using the criteria set forth in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5).1 However, these criteria were derived from children and young adults and not specifically targeted toward adults.
Qualified medical professionals who are best equipped to diagnose ADHD including physicians (psychiatrists, pediatricians, neurologists) and clinical psychologists. Social workers, nurse practitioners, school psychologists, and other licensed therapists (professional counselors, marriage and family therapists, etc.) can be helpful with initial screenings for the disorder and can provide referrals for a formal diagnosis.
The clinical diagnosis of ADHD is often made by assessing patient symptoms, severity of impairment, comorbidity (presence of other symptoms), family history, and psychosocial stressors. Pediatric evaluations typically consist of interviews with the patient and caregiver, behavioral observations, and a review of school, medical, and/or neuropsychological testing.
Treatment of ADHD
Behavior therapy has been identified over the last 20 years as being an evidence-based treatment for the symptoms of ADHD.10 Behavioral strategies, grounded in learning theory, includes a focus on procedures wherein parents and/or caregivers are trained to use specific strategies to increase desired behaviors (e.g., compliance, organization) and decrease undesirable behaviors (e.g., noncompliance, disruptions).
Several meta-analyses over the last decade have established that behavioral treatments result in moderate to substantial improvement for children who engage in a variety of disruptive and noncompliant behaviors.10 These types of therapies can be provided by licensed psychologists, social workers, and counselors with the appropriate educational background and training.
Numerous systematic reviews show that up to 70% of children respond well to stimulant medications, with short-term improvement in ADHD symptoms related to inattention and hyperactivity/impulsivity.11 Stimulant medications typically used to treat these symptoms include Methylphenidate (brand names: Ritalin, Quillivant, QuilliChew, Metadate, Concerta), Dextroamphetamine + Amphetamine (brand name: Adderall) and Dextroamphetamine (brand name: Dexedrine).
Additional types of medication for ADHD symptoms include atomoxetine (brand name: Strattera), an FDA-approved alternative to stimulant medication which replaces certain neurotransmitters in the brain, and guanfacine (brand name: Tenex), which is a blood pressure medication that is often prescribed off-label to treat ADHD.
These medications are associated with side effects, which include nervousness, insomnia, dry mouth, loss of appetite, constipation, and tachycardia. While a pediatrician is qualified to prescribe these medications, many will refer families to a specialist (i.e. developmental pediatricians and/or psychiatrists) for ongoing medication management.
ADHD Statistics
Attention-deficit/hyperactivity disorder is among the most common neurobehavioral disorders in children. ADHD affects an estimated 4% – 12% of school-aged children worldwide.12 In addition, data suggests that up to 5% of college-aged students and adults meet criteria for ADHD. The disorder is more frequent in males than in females, with a ratio of 2:1 in children and 1.6:1 in adults.1 In addition, females are more likely than males to present primarily with inattentive features.
Living with ADHD: Coping & Managing Symptoms
As ADHD is a chronic condition, many individuals with the diagnosis have ongoing difficulties throughout the lifetime.3 For those taking medication, it may become clear that symptoms shift with changes in the environment requiring ongoing management of dosages and types.
Younger children may require educational and/or behavioral supports at school, including an IEP or 504 plans. Adolescents and adults may consider informing administrators or employers about an ADHD diagnosis for accommodations to increase productivity.
Aside from more formal accommodations, individuals with ADHD can take measures on their own to support skills deficits. Common strategies to manage symptoms include note taking to address working memory deficits, structured scheduling to avoid procrastination, and use of technology and planners to support difficulty with organization. There are some games and exercises that purport to improve memory and attention, ranging from crossword puzzles and Sudoku to more expensive options like Lumosity© or BrainHQ©, though these activities do not claim to treat specific diagnoses.
Rating Scales & Checklists for ADHD
The following scales and checklists are used to help clinicians gather information on symptoms and functioning. Responses to these questionnaires are not sufficient by themselves to arrive at a diagnosis of ADHD, but can be an important component of the evaluation process:
- Child Behavior Checklist (CBCL): Identifies problem behavior in children ages 6-18 years. Includes possible diagnoses as well as internalizing/externalizing problems
- Conners’ Rating Scales
- Teacher Rating Scale: Revised, provides information from teachers on subscales relating to oppositional problems, cognitive problems, hyperactivity, and an ADHD-index
- Parent Rating Scale -Revised
- Adolescent Self-Report Scale
- Vanderbilt ADHD Rating Scales (VADRS)
- Parent Rating Scale: Gathers information on caregivers’ perspective of social functioning and school performance
- Teacher Rating Scale: Provides information on school performance and ADHD symptoms
- ADHD Rating Scale-IV (ADHD-RS-IV): Includes separate forms for parents/caregivers and teachers; divided into subscales for hyperactivity/impulsivity and inattentiveness
ADHD Resources
While only a professional can diagnose and treat Attention-Deficit/Hyperactivity Disorder, there are several organizations that can provide support and guidance.
These include:
- Children and Adults with Attention-Deficit/Hyperactivity Disorder (CHADD)
- Attention Deficit Disorder Association (ADDA)
- American Psychological Association (APA)
In addition, there are several places on the internet where you can “check your symptoms” to see if it would be appropriate to follow up with a professional.
Some examples include: